The problem of jointly optimizing a transmitter and a receiver so as to maximize the output signal-to-interference plus noise ratio (SINR) for target detection is an important one in radar and many communication scenes where clutter or multipath is a leading source of interference.
In radar scenarios, the total interference signal is comprised of clutter returns, interference signals from jammers and noise. The clutter return is transmit signal dependent and it may or may not dominate the remaining interference signals depending on the target range location. For targets that are nearby clutter dominates the total return, whereas for far field targets the returns from jammers and multipath is the leading source of interference. The interference caused by jammers might be deliberate multipath returns of a white noise source which in essence amount to colored noise with unknown spectrum at the receiver.
In the classical detection problem, the receiver outputs are passed through a bank of filters to obtain a single output and at a specified instant, this output is used to decide the presence or absence of a target. The problem is to design the optimal transmit-receiver pair so as to maximize the output signal-to-interference plus noise ratio (SINR) at the decision instant. In this context, for a given target and clutter/noise scene, the optimum transmit signal shapes as well as the receiver structure for maximizing the output detection performance is of crucial importance as discussed in (1). S. U. Pillai, H. S. Oh, D. C. Youla and J. R. Guerci, “Optimum Transmit-Receiver Design in the Presence of Signal-Dependent Interference and Channel Noise,” IEEE Transactions on Information Theory, vol. 46, no. 2, pp. 577–584, March 2000, and (2) J. R. Guerci and P. Grieve, “Optimum Matched Illumination-Reception Radars,” U.S. Pat. No. 5,121,125, June 1992, and U.S. Pat. No. 5,175,552, December 1992.